One of the prosecutors who brought the case against I. Lewis “Scooter” Libby says President Trump’s pardon of the ex-top aide to former Vice President Dick Cheney sends a not-so-subtle message to potential witnesses in special counsel Robert Mueller’s Russia investigation: Stay loyal to Trump and Trump will stay loyal to you.

Libby was convicted in 2007 of lying to investigators and obstruction of justice in the 2003 leak of covert CIA officer Valerie Plame’s identity. Then President George W. Bush later commuted Libby’s 30-month prison sentence, but did not issue a pardon.

“He already had his law license back,” Zeidenberg said. “It’s not a case, if you thought he was treated unjustly, that the poor guy is rotting in jail and is gonna die in prison. I mean, this isn’t a situation like that.”

Trump issued the full pardon to Libby on April 13 — four days after the FBI raid on the office and hotel of the president’s personal lawyer Michael Cohen.

“There was no urgency or critical need to step in right now except for what else was going on — Trump’s consigliere, Michael Cohen, had just gotten his office raided,” Zeidenberg said.

The raid led to speculation that Cohen could face federal charges related to the hush-money payment he made to porn star Stormy Daniels on the eve of the 2016 presidential election — and the possibility Cohen could strike a deal with prosecutors to incriminate Trump and mitigate his own sentence.

Over the weekend, Trump predicted that Cohen would not “flip” on him, and on Tuesday he sharply rejected a question from a reporter who asked whether he is considering pardoning Cohen.

“I don’t think it’s a reach to think he’s sending a message to others, and hoping they’ll stay strong and won’t cooperate and hold out hope for a pardon,” Zeidenberg said.

Zeidenberg said Trump’s pardon of Libby would likely not be a concern of Mueller’s investigation. But it would be if the president moved to pardon Cohen or any of those already charged in the case — like former National Security Director Michael Flynn, Trump campaign manager Paul Manafort, adviser Rick Gates or foreign policy aide George Papadopoulos.

“If he pardons Cohen, if he pardons Manafort, if he pardons Gates or any of these other guys — Flynn, Papadopoulos — any of these people, then at that point I think you’re getting much closer to an obstruction case,” Zeidenberg said.

Trump, as president, has the absolute authority to pardon anyone. But Zeidenberg said that a pardon could be evidence of obstruction, depending on the motive.

“The fact that the conduct in and of itself is legal is not the end of the inquiry,” Zeidenberg said. “If he’s doing it in the hope to thwart a legitimate investigation into his own conduct, then yeah, I think those are building blocks to an obstruction piece.”